Java println array string

How to print an array in java

This post will detail out different methods of printing array in java.
Method 1 : Using Arrays.toString method
java.util.Arrays class has a toString method which takes an array as argument and returns a string which is a representation of the array.
This representation is meaningful and consists of elements of array surrounded by square brackets.
Example,

import java.util.Arrays; public class ArrayToStringConverter { public static void main(String[] args) { String[] array = {"java", "python", "angular"}; System.out.println(Arrays.toString(array)); } }

import java.util.Arrays; public class ArrayToStringConverter < public static void main(String[] args) < String[] array = ; System.out.println(Arrays.toString(array)); > >

Method 2 : Using Arrays.asList method
java.util.Arrays class has a asList method which takes an array as argument and returns java.util.List object populated with the elements of array.
This list can be directly printed as shown below.

import java.util.Arrays; import java.util.List; public class ArrayToStringConverter { public static void main(String[] args) { String[] array = {"java", "python", "angular"}; // convert array to list List list = Arrays.asList(array); System.out.println(list); } }

import java.util.Arrays; import java.util.List; public class ArrayToStringConverter < public static void main(String[] args) < String[] array = ; // convert array to list List list = Arrays.asList(array); System.out.println(list); > >

The reason that the list prints the above output is that the super class of all list implementations, that is, java.util.AbstractCollection has an overridden toString method which returns the list in string format as printed in the output.

Method 3 : Using join method of String
java 8 introduced a new method join in java.lang.String class.
This is a static method which takes two arguments;
second argument is the array of String elements, and
first argument is the delimiter or the separator with which the elements of array are joined.
This method iterates over the array elements, combines them with the supplied delimiter and returns the combined string.
Example,

import java.util.Arrays; public class ArrayToStringConverter { public static void main(String[] args) { String[] array = {"java", "python", "angular"}; // join array elements with a comma String joinedString = String.join(", ", array); System.out.println(joinedString); } }

import java.util.Arrays; public class ArrayToStringConverter < public static void main(String[] args) < String[] array = ; // join array elements with a comma String joinedString = String.join(", ", array); System.out.println(joinedString); > >

With this approach, you can customize the separator between array elements.
Thus, if you want the array elements to be separated by a space, then supply a space as the first argument to the join method as shown below.

String joinedString = String.join(” “, array);

Method 4 : Using streams in java 8
java 8 also introduced the concept of streams which can be used to print a string array.
Example code which can be used to print array contents is given below.

import java.util.Arrays; import java.util.stream.Stream; public class ArrayToStringConverter { public static void main(String[] args) { String[] array = {"java", "python", "angular"}; Arrays.asList(array).stream().forEach(s ->; System.out.print(s + " ")); } }

import java.util.Arrays; import java.util.stream.Stream; public class ArrayToStringConverter < public static void main(String[] args) < String[] array = ; Arrays.asList(array).stream().forEach(s ->; System.out.print(s + » «)); > >

Above code converts array to a list using asList method and then creates a stream of this list using stream method.
This stream is then iterated using forEach method. In every iteration, the current array element is received into the lamba expression provided to forEach as argument.
Output is

Above code prints array elements separated with an empty space.
If you want the elements to be separated by a comma, then modify the forEach body as shown below.

Arrays.asList(array).stream().forEach(s ->; System.out.print(s + “, “));

Method 5 : Using for loop
This is a traditional method which iterates over an array using a for loop and prints the current element in every iteration.
This method is not a one-liner solution to print array.
Example,

public class ArrayToStringConverter { public static void main(String[] args) { String[] array = {"java", "python", "angular"}; // iterate over array for(String element: array) { System.out.print(element + " "); } } }

With this approach also, you can change the separator between elements of the array.

For any other method known to you, add in the comment box below.
Hit the clap below if you liked the article. Keep visiting.

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How to print array in java

In this post, we will see how to print array in java.

There are multiple ways to print an array. Let’s go through few ways to print array in java.

Using Arrays.toString()

You can use Arrays.toString() method to print array in java. This is simplest ways to print an array.
Arrays.toString() returns string object.This String contains array in string format.
Let us understand with the code

Using deepToString() method

Basically Arrays.toString() works fine for a 1-dimensional arrays,but it won’t work for multidimensional arrays.
Let’s say we have 2-dimensional array as shown
1 2 3
4 5 6
7 8 9
To convert multidimensional arrays to string, you can use Arrays.deepToString() method. This is how you can print 2D array in java.

Using Java 8 Stream API

In java 8, you can convert array to Stream and print array with Stream’s foreach() method.

Arrays . stream ( string2DArray ) . flatMap ( str — > Arrays . stream ( str ) ) . forEach ( System . out : : println ) ;

Arrays . stream ( int2DArray ) . flatMapToInt ( i — > Arrays . stream ( i ) ) . forEach ( System . out : : println ) ;

As you can see we have seen how to print String array and Integer array in java using Stream.

Using for loop

You can iterate the array using for loop and print elements of array in java.

Using for-each loop

For each works same as for loop but with differs syntax.

Print array in reverse order in java

You can iterate the array using for loop in reverse order and print the element. This will print array in reverse order.

Print array with custom objects

In case, you have custom object in the array, then you should override toString() method in custom class, else it will give you unexpected results.
Let’s see with the help of example
Create a simple class named Color.java

Create main class named PrintArrayOfColors.java

If you notice, we don’t have toString() method in Color class, that’s why it is calling Object’s toString() method and we are not able to see meaningful results.

We need to override toString() method in Color class and we will get informative output.

When you run PrintListOfColorsMain again, you will get below output:

As you can see, we have much meaningful output now.

That’s all about how to print array in java.

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